PMPro MailChimp

Specify the subscription list(s) for your site's WordPress Users and Paid Memberships Pro Members. If PMPro is installed you can specify additional list settings by membership level. Membership level ID and name merge fields are also added for each member on your list(s).

The plugin has a setting to require/not require MailChimp's double opt-in, as well as a setting to unsubscribe members on level change. This allows you to move members from list to list based on membership level. It is important to note that with this setting active the member will be unsubscribed from ALL other lists on membership level change and will only be subscribed to the list(s) set for their active membership level.